Valve-seat refacer



F. O. ALBERTSON VALVE SEAT REFACER Sept. 7 f, 192e. 1,599,266

Filed Nov. 24, 1924 lll n nl di e@ l /4 il im llll I A e I .es .to form a plurality 'so ally relative to the am's of the Patented Sept- 7, 19.26.

UNITED STATES PATENT oFFIcE.

rms o. ALBERT'soN, or sioux CITY, Iowa, Assrerron 'ro ALBERTsoN a coMPANY,

OF SIOUX CITY, IOWA, A.' CORPORATION OF IOWA. y i

vALvE-sna'r :ammonia Application led November 24,1924. Serial No. 751,785.

' ing the preferred embodiment of this valve seat refacer: Y

-Figure 1 `V is a' vertical sectional view through the valve port of an internal combustion engine showing m improved refacing tool in position on t e valve seat;

Figure 2 is a diametric section throu h the refacer, also showing a portion of t e supporting shank or bit;

igure is an end elevational viewof the refacing tool, and Figure'4 is 'a developed view showing the cutting face of the tool developed `into a single plane.

` The original blank or body of the refacer consists 'o a short cylindrical block of metal having a lower conical cutting face 7. This cutting rface has the same angle` of Obliquity as the valve seat to be refaced, which is generally or 60, these being the standard valve seat angles forthe majority of automobile en This blank 1s milled with a suitable hob of closely spaced cuts around the cutting facel'. Thel shape of the hob, or its cuttin angle, is such as to u form teeth 8 having .-'Aeading faces or edges 9 which lie in vertical planes extending radirefacer. The reverse side of each tooth is formed by 'an inclizgd back slope l0 extending inwardly and ackwardly to intersect the front face 9 of the next succeeding tooth. In the finished tool, these teeth have relatively narrow flat outer seat-engaging surfaces 11 which define the workin face of the tool.

Machined around the working face 7 the tops of the lteeth 8 is -a spiral 5c groove 12 which winds by successive con# volutions from the inner ends of the teeth outwardly to the outer ends thereof. As shown in Figs. 2 and 4, this groove forms a series of slpaced notches across the entire face of eac tooth 8, these notches 12 being chips outwardly of a width closelyv approaching the` width of i lthe metal intervening between the notches.

The spiral groove may lead outwardly in a clockwise direction, as viewedl in Fig. 3, so that the counter-clockwise rotation (Fig. 3) of the refacer will result in Jthe spiral groove feeding outwardly, ite.. if a-small chip or particle of metal should be caught 1n this 'groove and be retained therein i through several revolutions of the refacer, it would be carried outwardly along the valve seat and discharged at the outer edge, thereof. While this tendency to feed the and therebyV discharge them, exists in all of my refacers having the above described relation between the trend of the spiral groove and the direction of rotation of the tool, this featureis'not an essential part of my of practical 'value in tools having an angle of Obliquity of 15 degrees or thereabouts.

It will beobserved'from Figs. 3 and 4 that the successive notches 12 formed -in the upper edge of each tooth divide this edge into a series of separate cutting shoulders 14 spaced across the width of the tooth, each of these cutting shoulders having a substantially flat seat-engaging area 14 associated 'therewith. As clearly shown in the drawings, the surface of each seat-engaging area meets the leading face of its tooth in such a manner as to provide a pair of sharp corners or penetratingpoints 14". The action of these penetrating points is tok pierce the hard, crystallized surface of vthe valve seat and to permit the cutting edges of the teeth to get under and readily remove this crystallized surface. An important feature is the V- shaped contour of the groove which gives a maximum base area to the cutting shoulders and their associated seat -engaging areas, thereby tending to eliminate any breakage which might otherwise result from the severe strain to which said bases are subjected. Particular attention is directed to the width ofthe lseat-engaging areas, in a radial direction, relative to the' width of the valve seat. lin order to obtain the desired action of the refacer, it is essential that this width of the seat-engaging areas invention and is onlyf be substantially less than the width of the valve seat. This feature of this invention is clearly shown in Fig. 1. 1

In use, the refacer is usually mounted on a shank 15 of any suitable-form',-;.the one illustrated comprising an enlarged upper end 16 and a reduced stem end 17a For.

holding the refacer 6 fast on this shank, the central socket 18 of the refacer may have a slight taper, or the shank may havel a slight taper, whereby the two ma)7 be wedged together. The upper end of the shank has a square portion 19 for receiving the chuck of a power unit for driving the' tool. After the valve has been removed,

'the stem end 17 of the shank is inserted ;Inediately following these cutting shoulders are the slightly staggered shoulders lll-on the next succeeding tooth. Because of this slightly offset relation between the -cutting shoulders 14 on adjacent'teeth, these latter n teeth will make cuts on the valve seat at points further out on the valve seat. Thus each tooth makes a series of spaced cuts which slightly overlap the spaced cuts made by the preceding tooth,`and hence no one tooth cuts the entire width of the valve seat surface.- On a pitted, crystallized surface, having perhaps one or more 'high spots, this distributes the cutting effort between the teeth, leach tooth cutting a different section of the high spot.

I claim: 1

1. A tool for refacing a hardened and crystallized valve-seat comprising a cutting head, a shank adapted to be inserted in a valve-stem guide `associated with a valveseat to be refaced, said'head provided with a cutting face disposed at an angle corresponding to the angle of the valve to be refaced, a. plurality of teethformed in said cutting face, each of said teeth having'a substantiallyradial leading face and a seat engaging face at an edge-forming angle to said leading face, said seat-engaging face being notched to divide it into a plurality of' spaced' seat-engaging areas, each of which in the radial direc-tion, is of substantially less breadth than the seat to be refaced, the surface of each said spaced seat-engaging areas meetingits associated'leading face to provide a sharp cutting edge and a pair of penetrating points, the notches ofthe several teeth being disposed in spiral formation so that no one of said piercing points is tracked by acorresponding piercing point of a followinO tooth. f

2. tool vfor refacing a hardened and crystallized valve-seat comprising a cutting head, a shank adapted to be inserted in a valve-stem guide associated with a valveseat to be refaced, said head vprovided with a cutting face disposed at an angle correvide a sharp cutting edge and a pair of penetrating points, the notches of the seV- eral teeth being so disposed that no one of said piercing points is tracked by a corresponding piercing point of an adjacent tooth.

3'. A tool forv refacing a lhardened. and' 4meeting its associated leading face to procrystallized valve seat comprising a cutting edge, a shank adapted to be inserted in a valve stem guide associated with the valve seat to be refaced, said head provided with a cutting face disposed at an angle corresponding to the angle of the valve to be refaced,a plurality of teeth formed in said cutting face, each of said teeth having a substantiallyradial leading face and a seatengaging face at an edge-forming angleto said leadin face, saidseat-engaging face having notc es thereinto divide it into a plurality of spaced cutting shoulders, said notches being- V-shaped whereby the bases of said cutting shoulders are of maximum area.

and strength, spaced seat-engaging areas as- FRANS o; ALBERTSONV 

